I have a little question concerning timestamps in DCL program,
The DCL program I use is for receiving frames from an imaging device,
using DCAM protocol.
I have just added into the DCL program, a TimeStamp instruction, just
after the receive packets :
Receive packets * N
It works very well, and I receive perfectly well timestamp, with the
following format :
0000 SSSC CCCC CCCC CCCC 0000 0000 0000,
with S = seconds, from 0 to 7.
C = cycle count : unit = 1/8000 s (125 microsecs), from 0 to 7999
My question :
-> Knowing that I have many received packets for each frame, to what
packet does the DCL timestamp correspond to ? To the first packet,
the last packet, or none?
Is it possible to have a timestamp corresponding to the beginning of
first receive packet (beginning of frame transmission) ?
-> Unit for cycle count is 125 microsecs. What is the accuracy of
OHCI clock generating these cycles, compared to the computer system
clock, for instance ?
I thank you very much for your answers,
Wishing a happy new year to firewire list readers,